Display Having Optical Films With Bent Alignment Structures
An electronic device such as a laptop computer or other device may have a housing. A display may be coupled to the housing. The display may have a pixel array configured to display an image. Backlight illumination for the pixel array may be provide by a backlight unit. The backlight unit may have a light guide layer. A light source may provide light to an edge of the light guide layer. The light guide layer may scatter the light outwardly to serve as the backlight illumination for the pixel array. The backlight unit may have optical films interposed between the light guide layer and the pixel array. The optical films may include flexible polymer layers such as diffuser layers and prism films. The optical films may each have a bent alignment portion that bends back on itself while wrapping around an edge of the light guide layer.
This application claims the benefit of provisional patent application No. 62/781,350, filed Dec. 18, 2018, which is hereby incorporated by reference herein in its entirety.
FIELDThis relates generally to electronic devices, and, more particularly, to displays for electronic devices.
BACKGROUNDElectronic devices often include displays. For example, cellular telephones and computers may have displays for presenting information to a user.
Liquid crystal displays have arrays of pixels for presenting images. A backlight unit may be used to provide backlight illumination for the pixels. A backlight unit may contain a light guide layer. The light guide layer may have an edge that receives light from light-emitting diodes and that laterally distributes the light throughout the backlight unit. Optical films such as brightness enhancement films and diffuser layers may overlap the light guide layer. To ensure that the optical films are aligned satisfactorily and do not shift during use of the electronic device, the optical films may be provided with protruding alignment tabs. The alignment tabs may help secure the positions of the optical films, but can consume more lateral space within the electronic device than desired. This can cause the electronic device to have undesirably large inactive border areas.
SUMMARYAn electronic device such as a laptop computer or other device may have a housing. A display may be coupled to the housing. The display may have a pixel array configured to display an image. Backlight illumination for the pixel array may be provide by a backlight.
The backlight may have a light guide layer. A light source such as an array of light-emitting diodes may provide light to an edge of the light guide layer. The light that is received from the light-emitting diodes may be distributed throughout the light guide layer in accordance with the principle of total internal reflection. The light guide layer may having light scattering structures that scatter the light outwardly to serve as backlight illumination for the pixel array.
A stack of optical films such as diffusers and prism films may be interposed between the light guide layer and the pixel array. The optical films may be formed from flexible polymer layers. Edge portions of the flexible polymer layers may bent back on themselves to wrap around an edge of the light guide layer. The optical films may, for example, each have a bent alignment portion that bends back on itself while wrapping around an edge of the light guide layer. The bent alignment portions may include bent edge portions that extend along some or all of the length of the edge of the light guide layer and may include bent protruding tabs.
The bent alignment portions may be coupled to the housing of the electronic device to align the optical films with respect to the housing. This helps prevent misalignment and film wrinkling during use of the electronic device. Adhesive structures such as layers of adhesive and/or adhesive on strips of tape may be used to attach the bent alignment portions to the housing.
If desired, electronic device housings, electronic components, alignment members embedded in display trim members, and/or other structures may serve as alignment posts that are received within alignment openings in the optical films.
Electronic devices may include displays. The displays may be used to display images to a user. An illustrative electronic device with a display is shown in
Housing 12 may be a stand-alone housing (e.g., in scenarios in which device 10 is a cellular telephone or tablet computer), may form an upper portion of a two-part housing (e.g., housing 12 may be the upper portion of a laptop housing that also has a lower portion such as lower laptop housing 12L that is coupled to the upper portion by a hinge that allows the upper and lower portions to rotate with respect to each other about hinge axis 24), may be supported on a stand (e.g., when housing 12 forms a desktop computer housing), may be coupled to straps (e.g., when housing 12 forms a wristwatch enclosure or a housing in a head-mounted device), and/or may have other suitable shapes.
In general, electronic device 10 may be a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch device, a pendant device, a headphone or earpiece device, a head-mounted device, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment.
Housing 12 of device 10, which is sometimes referred to as a case, may be formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other fiber-based composites, metal (e.g., machined aluminum, stainless steel, or other metals), other materials, or a combination of these materials. Device 10 may be formed using a unibody construction in which most or all of housing 12 is formed from a single structural element (e.g., a piece of machined metal or a piece of molded plastic) or may be formed from multiple housing structures (e.g., outer housing structures that have been mounted to internal support structures or other internal housing structures).
Display 14 may be a touch sensitive display that includes a touch sensor or may be insensitive to touch. Touch sensors for display 14 may be formed from an array of capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch sensor components.
Display 14 for device 10 may include pixels formed from liquid crystal display (LCD) components or other suitable pixel structures. The pixels may be formed in a pixel array having a rectangular shape, a circular shape, an oval shape, a shape with curved and/or straight edges, a shape with one or more recesses (e.g., a notch), a shape with rounded corners or straight corners, a shape with openings to accommodate speakers and/or other components, and/or other suitable shapes. Display 14 may include an active area such as active area AA (e.g., a rectangular region or a region of other suitable shape that includes rows and columns of pixels forming a pixel array). During operation, the pixels of active area AA display an image for a user of device 10. Active area AA may be surrounded on one or more sides by inactive borders or other display regions that do not contain pixels and that do not emit light for forming images. These inactive display regions are shown as inactive area IA of
A display cover layer may cover the surface of display 14 or a display layer such as a thin-film transistor layer, color filter layer, or other portion of a display may be used as the outermost (or nearly outermost) layer in display 14. The outermost display layer may be formed from a transparent glass sheet, a clear polymer layer, a transparent structure formed from sapphire or other crystalline material, a transparent ceramic layer, or other transparent member. Coatings such as antismudge coatings, antireflection coatings, and/or antiscratch coatings may be formed on the outermost layer of display 14 and/or other layers of display 14.
A cross-sectional side view of an illustrative configuration for display 14 of device 10 is shown in
Display layer 46 may be mounted in chassis structures such as a plastic chassis structure and/or a metal chassis structure to form a display module for mounting in housing 12 of
In a configuration in which display layer 46 forms a liquid crystal display, display layer 46 may include a liquid crystal layer interposed between upper and lower layers formed from glass, transparent polymer, or other substrate materials. These upper and lower layers may include thin-film transistor circuitry for forming pixel circuits for pixels P and a color filter array that allows pixels P to display color images. The color filter array and pixel circuits may be formed on a common substrate and/or may be formed on separate substrates located on opposing sides of the liquid crystal layer. The liquid crystal layer and the upper and lower substrate layers may be interposed between opposing upper and lower polarizer layers (e.g., layer 46 may include upper and lower polarizers, upper and lower substrates such as a thin-film transistor layer and a color filter layer and/or other layers with thin-film transistor circuitry and color filter elements for pixels P, and a liquid crystal layer interposed between the upper and lower substrates). Touch sensor electrodes may also be incorporated into layer 46 and/or may be formed on a separate layer in display 14.
During operation of display 14 in device 10, control circuitry (e.g., one or more integrated circuits on a printed circuit) may be used to generate information to be displayed on display 14 (e.g., display data). The information to be displayed may be conveyed to one or more display driver integrated circuits and other display driver circuitry (e.g., thin-film gate drivers, etc.) using a signal path such as a signal path formed from conductive metal traces in a rigid or flexible printed circuit.
Backlight structures 42, which may sometimes be referred to as a backlight unit or backlight, may include a light guide layer such as light guide layer 78. Light guide layer 78 may be formed from a transparent material such as clear glass or polymer (e.g., a thin flexible polymer film or a plate formed from a sheet of transparent glass or polymer). During operation of backlight structures 42, a light source such as light source 72 may generate light 74. Light source 72 may be, for example, an array of light-emitting diodes. If desired, light sources such as light source 72 may be located along multiple edges of light guide layer 78.
Light 74 from light source 72 may be coupled into edge surface 76 of light guide layer 78 and may be distributed in dimensions X and Y throughout light guide layer 78 due to the principle of total internal reflection. Light guide layer 78 may include light-scattering structures such as pits, grooves, or other recess and/or bumps, ridges, or other protrusions. Light scattering structures such as glass particles, microspheres, air bubbles, and/or other structures may also be incorporated within light guide layer 78 to help scatter light 74. The light-scattering structures may be located on an upper surface and/or on an opposing lower surface of light guide layer 78 and/or may be embedded within light guide layer 78.
Light 74 that scatters upwards in direction Z from light guide layer 78 may serve as backlight illumination 44 for display 14. Light 74 that scatters downwards may be reflected back in the upward direction by a reflective film such as reflector 80. Reflector 80 may be formed from a reflective material such as a reflective layer of white plastic, from a thin-film mirror (e.g., a thin-film mirror formed from a stack of dielectric materials), and/or other reflective structures.
To enhance backlight performance for backlight structures 42, backlight structures 42 may include optical films 70. Optical films 70 may include one or more layers of transparent material through which backlight illumination 44 passes between light guide layer 78 and display layer 46 (e.g., flexible polymer films). Optical films 70 may include diffuser layers for helping to homogenize backlight illumination 44 and thereby reduce hotspots and one or more prism films (sometimes referred to as brightness enhancement films) for collimating backlight illumination 44. Compensation films for enhancing off-axis viewing may be included in optical films 70 or may be incorporated into other portions of display 14 (e.g., in polarizer layers in layer 46). In an illustrative configuration, optical films 70 include a first film adjacent to layer 78 such as a diffuser layer, second and third films such as brightness enhancement layers (prism films) that are located above the diffuser layer, and a fourth film above the brightness enhancement layers and adjacent to layer 46. Other configurations for optical films 70 may be used, if desired. Each optical film 70 may be sufficiently thin to be bent back on itself. For example, each optical film 70 may have a thickness of 30-150 microns, at least 20 microns, at least 40 microns, at least 50 microns, less than 300 microns, less than 200 microns, less than 150 microns, or other suitable thickness.
Display 14 may have a protective display cover layer such as layer 52. Layer 52 may be formed from glass, transparent polymer, transparent ceramic, crystalline material such as sapphire, and/or other transparent projective member that overlaps pixels P of display layer 46. If desired, layer 52 may be omitted and one or more layers of display layer 46 may be provided with sufficient thickness to strengthen layer 52 and thereby allow layer 52 to serve as the outermost layer of device 10. To hide internal structures in device 10 from view (e.g., display drive circuitry, interconnect lines, etc.), it may sometimes be desirable to form opaque masking layers on portions of the layers in display 14. As shown in
If desired, device 10 and the display structures in device 10 may have support structures (sometimes referred to as chassis structures, support structures, housing structures, frame structures, etc.). Consider, as an example, the arrangement of
To prevent optical films 70 from shifting during use (e.g., moving excessively in the X-Y plane of
The alignment portions, which may sometimes be referred to as bent alignment portions, may form bent protruding tabs or other alignment portions that are wrapped around the edge of light guide layer 78 so that the alignment portions of the light guide layer fold back on themselves after wrapping around light guide layer 78. By configuring protruding tabs on optical films 70 to double back on themselves (e.g., when viewed from above along dimension Z), these tabs do not extend excessively in lateral dimensions X and Y, thereby helping to minimize inactive border regions in display 14. At the same time, the presence of the alignment portions of optical films 70 may help align and secure films 70 at desired locations within display 14 and device 10.
Alignment portions 70P may be formed from a single strip-shaped edge portion of optical film 70 that is bent about a bend axis such as bend axis 104 of
Tape (e.g., pressure sensitive adhesive on a polymer film substrate), a layer of pressure sensitive adhesive, other adhesive, pins or other physical alignment structures, fasteners, and/or other attachment mechanisms may be used to attach each optical film 70 to support structure 100 (e.g., a display chassis or other internal housing structure, a housing wall in housing 12, and/or other support structure). Consider, as an example, the cross-sectional side view of the portion of backlight structures 42 that is shown in
Illustrative layers for use in backlight structures 42 are shown in
As shown in
To prevent visible artifacts where light escapes between adjacent tabs of films 70, the strip-shaped bent edge portion of lowermost film F1 that forms bent alignment portion 70P of
As described in connection with
To allow for potential expansion and contraction of films 70 during changes in temperature (due to the non-zero coefficient of thermal expansion that may be associated with films 70), it may be desirable to attach one or more bent alignment portions of films 70 to support structure 100 with a sliding joint such as sliding joint 134 of
In the illustrative configuration used for sliding joint 134 of
As shown in
Illustrative layouts for optical films 70 that may be used in a notched display such as display 14 of
As shown in
In the example of
As shown in
Device 10 may be operated in a system that uses personally identifiable information. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.
In accordance with an embodiment, a display is provided that includes a backlight having a light source, a light guide layer that receives light from the light source and that produces corresponding backlight illumination, pixels that are illuminated with the backlight illumination and that are configured to display an image, and optical films interposed between the backlight and the pixels, the optical films include bent alignment portions that wrap around an edge of the light guide layer.
In accordance with another embodiment, the optical films include a first optical film and a second optical film, the first optical film is interposed between the light guide layer and the second optical film, the edge of the light guide layer has a length and extends between opposing first and second sides of the light guide layer, the first optical film has a bent edge portion that runs along the length of the edge of the light guide layer while wrapping around the edge of the light guide layer, and the second optical film has bent protruding tabs that wrap around respective portions of the edge of the light guide layer.
In accordance with another embodiment, the optical films include a prism film and a diffuser film.
In accordance with another embodiment, the diffuser film has a bent edge portion wrapped around the edge of the light guide layer.
In accordance with another embodiment, the prism film includes first and second bent protruding tabs wrapped around the edge of the light guide layer, a first portion of the bent edge portion is interposed between the first bent protruding tab and the light guide layer, and a second portion of the bent edge portion is interposed between the second bent protruding tab and the light guide layer.
In accordance with another embodiment, the display includes a reflector, the light guide layer and the optical films are interposed between the reflector and the liquid crystal display pixels.
In accordance with an embodiment, an electronic device is provided that includes a support structure, an array of pixels configured to display an image, and a display backlight having a light guide layer that is configured to provide backlight illumination to the array of pixels and having flexible polymer films that are between the light guide layer and the pixels and that have bent alignment portions that wrap around an edge of the light guide layer and are coupled to the support structure.
In accordance with another embodiment, the support structure includes an electronic device housing.
In accordance with another embodiment, the electronic device includes adhesive that attaches the flexible polymer films to the support structure.
In accordance with another embodiment, at least one of the bent alignment portions include a bent protruding tab.
In accordance with another embodiment, the bent protruding tab wraps around the edge and is bent back on itself and the adhesive is configured to attach the bent protruding tab to the electronic device housing.
In accordance with another embodiment, the bent alignment portions include a bent protruding tab, the electronic device includes tape that is configured to couple the bent protruding tab to the electronic device housing.
In accordance with another embodiment, the tape has a non-sticky portion that overlaps the bent protruding tab to form a sliding joint that couples the bent protruding tab to the support structure while allowing the bent protruding tab to slide relative to the support structure.
In accordance with another embodiment, the light guide layer has a notch and the bent alignment portions overlap a portion of the edge in the notch.
In accordance with another embodiment, the light guide layer has a notch and the bent alignment portions overlap portions of the edge out of the notch.
In accordance with an embodiment, an electronic device is provided that includes a housing member, and a display in the housing having a backlight that produces backlight illumination and having a pixel array that is illuminated by the backlight illumination, the backlight includes a light-emitting diode, a light guide layer that receives light from the light-emitting diode and that provides the backlight illumination to the pixel array, and a flexible polymer layer interposed between the light guide layer and the pixel array, the flexible polymer layer has a bent protruding tab that is bent around an edge of the light guide layer and that is secured to the housing member.
In accordance with another embodiment, the electronic device includes adhesive that is configured to secure the bent protruding tab to the housing member.
In accordance with another embodiment, the flexible polymer layer includes a prism film.
In accordance with another embodiment, the electronic device includes tape, the housing member includes a housing wall, and the flexible polymer layer is secured to the housing wall using the tape.
In accordance with another embodiment, the flexible polymer layer includes one of at least four optical films interposed between the light guide layer and the pixel array and the optical films include at least two diffusers and at least two prism films each of which has a respective bent alignment portion coupled to the housing member.
The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.
Claims
1. A display, comprising:
- a backlight having a light source, a light guide layer that receives light from the light source and that produces corresponding backlight illumination;
- pixels that are illuminated with the backlight illumination and that are configured to display an image; and
- optical films interposed between the backlight and the pixels, wherein the optical films include bent alignment portions that wrap around an edge of the light guide layer.
2. The display defined in claim 1 wherein the optical films include a first optical film and a second optical film, wherein the first optical film is interposed between the light guide layer and the second optical film, wherein the edge of the light guide layer has a length and extends between opposing first and second sides of the light guide layer, wherein the first optical film has a bent edge portion that runs along the length of the edge of the light guide layer while wrapping around the edge of the light guide layer, and wherein the second optical film has bent protruding tabs that wrap around respective portions of the edge of the light guide layer.
3. The display defined in claim 1 wherein the optical films include a prism film and a diffuser film.
4. The display defined in claim 3 wherein the diffuser film has a bent edge portion wrapped around the edge of the light guide layer.
5. The display defined in claim 4 wherein the prism film comprises first and second bent protruding tabs wrapped around the edge of the light guide layer, wherein a first portion of the bent edge portion is interposed between the first bent protruding tab and the light guide layer, and wherein a second portion of the bent edge portion is interposed between the second bent protruding tab and the light guide layer.
6. The display defined in claim 1 wherein the pixels comprise liquid crystal display pixels, the display further comprising a reflector, wherein the light guide layer and the optical films are interposed between the reflector and the liquid crystal display pixels.
7. An electronic device, comprising:
- a support structure;
- an array of pixels configured to display an image; and
- a display backlight having a light guide layer that is configured to provide backlight illumination to the array of pixels and having flexible polymer films that are between the light guide layer and the pixels and that have bent alignment portions that wrap around an edge of the light guide layer and are coupled to the support structure.
8. The electronic device defined in claim 7 wherein the support structure comprises an electronic device housing.
9. The electronic device defined in claim 8 further comprising adhesive that attaches the flexible polymer films to the support structure.
10. The electronic device defined in claim 9 wherein at least one of the bent alignment portions comprises a bent protruding tab.
11. The electronic device defined in claim 10 wherein the bent protruding tab wraps around the edge and is bent back on itself and wherein the adhesive is configured to attach the bent protruding tab to the electronic device housing.
12. The electronic device defined in claim 8 wherein the bent alignment portions comprise a bent protruding tab, wherein the electronic device comprises tape that is configured to couple the bent protruding tab to the electronic device housing.
13. The electronic device defined in claim 12 wherein the tape has a non-sticky portion that overlaps the bent protruding tab to form a sliding joint that couples the bent protruding tab to the support structure while allowing the bent protruding tab to slide relative to the support structure.
14. The electronic device defined in claim 7 wherein the light guide layer has a notch and wherein the bent alignment portions overlap a portion of the edge in the notch.
15. The electronic device defined in claim 7 wherein the light guide layer has a notch and wherein the bent alignment portions overlap portions of the edge out of the notch.
16. An electronic device, comprising:
- a housing member; and
- a display in the housing having a backlight that produces backlight illumination and having a pixel array that is illuminated by the backlight illumination, wherein the backlight comprises a light-emitting diode, a light guide layer that receives light from the light-emitting diode and that provides the backlight illumination to the pixel array, and a flexible polymer layer interposed between the light guide layer and the pixel array, wherein the flexible polymer layer has a bent protruding tab that is bent around an edge of the light guide layer and that is secured to the housing member.
17. The electronic device defined in claim 16 further comprising adhesive that is configured to secure the bent protruding tab to the housing member.
18. The electronic device defined in claim 17 wherein the flexible polymer layer comprises a prism film.
19. The electronic device defined in claim 16 further comprising tape, wherein the housing member comprises a housing wall, and wherein the flexible polymer layer is secured to the housing wall using the tape.
20. The electronic device defined in claim 16 wherein the flexible polymer layer comprises one of at least four optical films interposed between the light guide layer and the pixel array and wherein the optical films include at least two diffusers and at least two prism films each of which has a respective bent alignment portion coupled to the housing member.
Type: Application
Filed: May 14, 2019
Publication Date: Jun 18, 2020
Patent Grant number: 11003208
Inventors: Keith J. Hendren (San Francisco, CA), Adam T. Garelli (Morgan Hill, CA), Bryan W. Posner (San Francisco, CA), Dinesh C. Mathew (San Francisco, CA), Mengyang Liang (Sunnyvale, CA), Eric Benson (San Mateo, CA), Victor Yin (Cupertino, CA), Jun Qi (San Jose, CA)
Application Number: 16/412,285